No abstract

No abstract

Equilibrium adsorption studies of N-hydrocinnamoyl-N -phenylhydroxylamine (HCNPHA) on galena, sphalerite, pyrite, chalcopyrite and quartz at pH 9 and 10 are reported. All adsorption isotherms followed Langmuir model, however, Freundlich type was observed for quartz. As HC-NPHA is a strong chelating agent, formation of monolayers by chemisorption appeared to be the most probable mechanism of adsorption on the base-metal sulphide minerals. Specific adsorption of HCNPHA on iron containing minerals, namely, chalcopyrite and pyrite, was about three times that on galena and sphalerite, and specific adsorption on quartz was the lowest amongst the minerals studied. Specific adsorptions (in µmol/g) of HCNPHA on the minerals at pH 9 are: sphalerite: 30.5; galena: 26.9; chalcopyrite: 112.3; pyrite: 145.4; quartz: 2.9. Compared to pH 9, specific adsorption of HCNPHA on the minerals decreased at pH 10, indicating hydroxylation of mineral sites due to higher hydroxide ion concentration at pH 10. A spectral-colorimetric procedure was developed for the quantitative estimation of HCNPHA. Due to deprotonation of hydroxamic acids direct estimation using UV absorption was not possible. Hence, complexation of HCNPHA with Fe 3+ was used to develop a purple coloured complex that absorbs in the visible region with λ max = 500 nm. Change in concentration of HC-NPHA was measured from absorbance of the HCNPHAFe 3+ complex at 500 nm. Electronic supplementary materialThe online version of this article (

Electrocatalytically active interface in a heterostructure is extremely crucial to obtain optimum adsorption energy of intermediates (O*, OH*, and HOO*) and faster electron transfer. Due to the slow kinetics of...

No abstract